Cliffs on Mercury Named for Carnegie Research Ship

Washington, D.C.—The International Astronomical Union (IAU) names celestial bodies and formations on planets. The IAU naming theme for cliffs, called “rupes,” on Mercury is "ships of discovery." On June 3 the IAU approved ten new names for rupes on the innermost planet. One in Mercury's northern hemisphere was named for the research vessel Carnegie that mapped the Earth’s magnetic field across the oceans in the early part of the last century. The feature on Mercury, now named Carnegie Rupes, is 166 miles long (267 km) long and over 6,600 feet (2,000 m) high in places.

The surface of Mercury hosts thousands of cliff-like rupes, which range in length from tens to many hundreds of miles. They are believed to have formed when blocks of crust thrust up and over each other in response to the global contraction of the planet as its interior cooled and solidified.

The Carnegie was a brigantine yacht composed almost entirely of non-magnetic material and was built for the Carnegie Institution's Department of Terrestrial Magnetism in 1909. Oceanic magnetic data acquired in a series of cruises aboard the Carnegie from 1909 to 1929 contributed to the first comprehensive map of Earth's magnetic field.

The proposal to name a rupes after the Carnegie was made by Sean C. Solomon, a former director of the Department of Terrestrial Magnetism and the principal investigator of the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) mission. Solomon is a former director of the Department of Terrestrial Magnetism. The name was featured in a proposal to the IAU to which two MESSENGER postdoctoral team members contributed. The MESSENGER spacecraft is now circling Mercury and collecting data about the planet’s geology, chemistry, magnetic field and more.

The current director of the department Linda Elkins-Tanton remarked, “The naming of Carnegie Rupes for DTM's ship of discovery is particularly fitting as this feature is currently being studied by MESSENGER team members based here at the department to gain a fuller understanding of the geological history of Mercury.”
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